Childhood obesity is widely recognised as a major contributor towards cardiovascular diseases, diabetes, sleep disorders, and psychological and social problems. The China National Nutrition and Health survey in 2002 revealed that the prevalence of overweight individuals has increased overall by 39% in the past ten years.

In Xi'an City, where the new study was conducted, 20% of the adolescents were found to be overweight, a rate similar to that observed in many western countries. In a recent report in the European Journal of Clinical Nutrition, researchers found the following factors were significantly associated with overweight and obesity in children included:

living in urban districts

limited use of sports facilities in schools

wealthier households

having an obese/overweight parent

having soft drink >4 times a week and not being fussy about foods.

Co-author of the research, Dr Ming Li, Research Fellow, at The George Institute for International Health in Sydney, explained that these risk factors should guide the future development of evidence-based and cost-effective strategies to tackle this increasing public health problem in China. Dr Li said that "Predictors of excess weight and obesity are widely acknowledged as heredity, lifestyle and environmental factors. However, these factors need to be viewed more closely, as they are greatly influenced by parents in a family, teachers at school, which are embedded in a community, and social context."

"Strategies that target socio-economic and behavioural factors alone do not seem to be effective in the long-term and are simply not sufficient. A stronger focus on community, school and household environments is vital to reduce the growing obesity epidemic. This is particularly important for a society that is undergoing such a massive nutritional transition," she noted.

The published research recommends that obesity intervention programs should include:

coordinated government policy-making for infrastructure development and food supply;

involvement of schools in the development of curriculum and school policies; and

family involvement, with a parenting approach that fosters a healthy lifestyle for children at the early stage of their life, to benefit them for the whole of their life.

Dr Li highlights the associated factors at the school level, such as the hours spent in class versus physical activity: "Chinese students spend around 8-9 hours a day at school. Obesity prevention strategies should really include the need to adjust school curricula to increase the opportunity for physical activity during the school day. Limited use of school sports facilities increased the risk of obesity by 70%."

"In addition, adolescents were more likely to be overweight or obese in urban and suburban areas, due to increased passive transport to school, easy access to fast food and also students in these areas are more likely to spend more time doing homework and have less physical activity." Dr Li added.

Parental control of "snacking" was reported to be strongly associated with adolescent obesity, especially in boys. "Parent's expression of nurturing emotion with clear communication and realistic behavioural expectations is imperative in a child's development and healthy behaviour. It provides motivation for the child, allows the parents to help establish healthy behaviours and reinforces self-regulation, thereby allowing the child to develop new and healthy activities," Dr Li noted.

Unlike findings from western countries, higher parental education was associated with overweight and obesity in adolescents. Eating and exercise behaviours can be shaped and cultivated by good family habits based on the parents' knowledge and practice.